The invention relates to a new .DELTA..sup.4 -oxazolin-2-ones and a process for their preparation.
As is known, the reaction of acyloines with carbamic acid derivatives or isocyanates leads to .DELTA..sup.4 -oxazolin-2-ones which are substituted in the 4,5-position. For example, 4,5-dialkyl- and 4,5-diaryl-.DELTA..sup.4 -oxazolin-2-ones have been obtained in this way (see Chem. Ber. 89, 1,748 (1956)). It is also known to prepare .DELTA..sup.4 -oxazolin-2-ones which are alkylated in the 3-position from 4-halogeno-dioxol-2-ones and primary amines (see German Offenlegungsschrift 2,304,589). A further process which is known for the preparation of .DELTA..sup.4 -oxazolin-2-ones is the photoisomerisation of 3-hydroxyisoxazoles: in connection with the isolation of active compounds of fly agaric which act on the central nervous system, muscazone, that is to say (.DELTA..sup.4 -oxazolin-2-on-5-yl)-glycine, has been obtained by exposing ibotenic acid to light (Helv. Chim. Acta 50, 137 (1967)). However, the processes described for the preparation of the substituted .DELTA..sup.4 -oxazolin-2-ones known hitherto cannot be used for synthesis of the parent compound, that is to say .DELTA. .sup.4 -oxazolin-2-one, and its N-acyl compounds, which have not been known hitherto.